wilful

Synonyms:
1. volitional. 2. intransigent; contrary, refractory, pigheaded, inflexible, obdurate, adamant. Willful, headstrong, perverse, wayward refer to one who stubbornly insists upon doing as he or she pleases. Willful suggests a stubborn persistence in doing what one wishes, esp. in opposition to those whose wishes or commands ought to be respected or obeyed: that willful child who disregarded his parents' advice. One who is headstrong is often foolishly, and sometimes violently, self-willed: reckless and headstrong youths. The perverse person is unreasonably or obstinately intractable or contrary, often with the express intention of being disagreeable: perverse out of sheer spite. Wayward in this sense has the connotation of rash wrongheadedness that gets one into trouble: a reform school for wayward girls.

Antonyms:
2. obedient, tractable.